题解 | #两个链表的第一个公共结点#

用一个Set临时存一下，在遍历第二个链表的时候判断set里有没有就行了XD

import java.util.*;
/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) {
         Set<ListNode> set1 = new HashSet<>();
         while(pHead1!=null){
             set1.add(pHead1);
             pHead1 = pHead1.next;
         }
        while(pHead2!=null){
            if(set1.contains(pHead2)){
                return pHead2;
            }
             pHead2 = pHead2.next;
         }

        return null;
    }
}